Ruby-crowned Kinglet (Regulus calendula)

My impression of this bird's nature, in regards to behavior towards humans, has changed through my encounters. My first impression was that they were somewhat curious. I had a few encounters where the kinglet would hover or perch close up to me as if to check me out. I also got the impression that kinglets have a "high people tolerance" since I can follow them closely and they do not seem bothered. Lately, however, I have gained the impression that they are perhaps "ignorant"--it's as if the kinglets have no awareness of my presence. This comes out of experience with this particular bird, which will fly right up to me as if he doesn't see me until just before he collides into me. In fact during this photo session he did his "flycatching" manuver right above my head, his wings brushing my hair! I know this is not any kind of defensive behavior. The "flybys" are insect-catching manuvers; sometimes I get in the way I guess (so I try to give the bird some space). It just seems as though the bird does its thing without any notion that there's this big human taking its picture; although it may appear in these images that he is posing for me :)